From c90182792b9f2985f0353b722433e8ed384829ef Mon Sep 17 00:00:00 2001
From: lberki <lberki@google.com>
Date: Fri, 19 Feb 2021 02:33:02 -0800
Subject: [PATCH] Make the Merkle tree computation work in the wake of
 https://github.com/bazelbuild/bazel/commit/7149f578006a4ad0d51df69830a6986749b34df5
 .

Fixes a bunch of downstream breakages:

https://github.com/bazelbuild/continuous-integration/issues/1093
https://github.com/bazelbuild/continuous-integration/issues/1094
https://github.com/bazelbuild/rules_nodejs/issues/2464
https://github.com/bazelbuild/rules_python/issues/419

Turns out, the assertion that "Merkle tree computation uses `ActionInput.getExecPath()`" was only mostly correct: there was a place where the key of the input map was used instead.

I'm somewhat surprised that this did not show up in our test battery, although, admittedly, "unsound directory as an input file in an external repository" doesn't sound like the most common use case.

RELNOTES: None.
PiperOrigin-RevId: 358366246
---
 .../merkletree/DirectoryTreeBuilder.java      |  2 +-
 src/test/shell/bazel/disk_cache_test.sh       | 25 +++++++++++++++++++
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/main/java/com/google/devtools/build/lib/remote/merkletree/DirectoryTreeBuilder.java b/src/main/java/com/google/devtools/build/lib/remote/merkletree/DirectoryTreeBuilder.java
index 2522bd3fb90d50..1ddcf963520079 100644
--- a/src/main/java/com/google/devtools/build/lib/remote/merkletree/DirectoryTreeBuilder.java
+++ b/src/main/java/com/google/devtools/build/lib/remote/merkletree/DirectoryTreeBuilder.java
@@ -146,7 +146,7 @@ private static int buildFromActionInputs(
 
             case DIRECTORY:
               SortedMap<PathFragment, ActionInput> directoryInputs =
-                  explodeDirectory(path, execRoot);
+                  explodeDirectory(input.getExecPath(), execRoot);
               return buildFromActionInputs(
                   directoryInputs, metadataProvider, execRoot, digestUtil, tree);
 
diff --git a/src/test/shell/bazel/disk_cache_test.sh b/src/test/shell/bazel/disk_cache_test.sh
index 303134057ad74c..05c6546ebe5f73 100755
--- a/src/test/shell/bazel/disk_cache_test.sh
+++ b/src/test/shell/bazel/disk_cache_test.sh
@@ -66,4 +66,29 @@ EOF
   assert_equals "0" $(cat "${execution_file}")
 }
 
+function test_input_directories_in_external_repo_with_sibling_repository_layout() {
+  create_new_workspace
+  l=$TEST_TMPDIR/l
+  mkdir -p "$l/dir"
+  touch "$l/WORKSPACE"
+  touch "$l/dir/f"
+  cat > "$l/BUILD" <<'EOF'
+exports_files(["dir"])
+EOF
+
+  cat >> WORKSPACE <<EOF
+local_repository(name="l", path="$l")
+EOF
+
+  cat > BUILD <<'EOF'
+genrule(name="g", srcs=["@l//:dir"], outs=["go"], cmd="find $< > $@")
+EOF
+
+  bazel build \
+    --experimental_sibling_repository_layout  \
+    --disk_cache="$TEST_TMPDIR/cache" \
+    //:g || fail "build failed"
+
+}
+
 run_suite "local action cache test"